• Corrosion Science and Technology
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• v.3 no.1
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• pp.14-19
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• 2004

Crack growth rate and threshold stress intensity factor for stress corrosion cracking(SCC), $K_{ISCC}$ were measured for type 403 stainless steel in 3,5% NaCl solution at room temperature and SCC was monitored by electrochemical noise technique during $K_{ISCC}$ testing. In rising load test, pits were formed at the tip of pre-crack for the pre-cracked compact tension specimen unlike in smooth round specimen in which only unstable pits were observed and hence immune to SCC. Micro-cracks were found to initiate from the pits in the former specimen, and initiation of micro-crack as well as macro-crack was detected by electrochemical noise technique in rising load $K_{ISCC}$ tests. Crack growth rate increased with increasing either displacement rate or stress intensity factor at crack initiation and was higher in rising load $K_{ISCC}$ test compared to constant load $K_{ISCC}$ test at given stress intensities.

• Journal of architectural history
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• v.8 no.2 s.19
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• pp.59-72
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• 1999

The purpose of this study is to find the spatial factors, strucure of living and activity in traditional Korean house through the Phiysiological view, Spatial factors of the house are concerned to the interior environment and sanitary condition, The elements of respiratory, nerve, temperature sence. vision, hearing, smelling have good condition and touch, pressure sence, pain, metabolism are poor in the house, Ventilation, Lighting, pleasant condition of interior environment are concerned to the elements that mentioned above and have most important meaning in the relation rate of space as 1st factor. And 2nd factor is for metabolism, housework and rest, 3rd factor ie for temperature sence, privacy and reproduction. The relation rate of factors concering interior environment are high in the upper class house. Anbang has important meaning in the relation of living structure and relation sequence of space is anbang, Konnonbang, kitchen, toilet, water place, auxiliary buildings. The relation rate of activity is high in interior space in winter and exterior space in summer.

• Journal of Ocean Engineering and Technology
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• v.5 no.2
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• pp.58-66
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• 1991

Not only difference of fatigue crack growth and propagation behavior resulted from the grain size, the hardness ratio and volume fraction in M.E.F. dual phase steel composed of martensite in hard phase and ferrite in soft phase, but also the effects of the plastic constraint were investigated by fracture mechanics and microstructural method. The main results obtained are as follows: 1) The fatigue endurance of M.E.F. steel increases with decreasing the grain size, increasing the ratio of hardness and volume fraction. 2) The initiation of slip and crack occures faster as the stress level goes higher. These phenomena result from the plastic constraint effect of the second phase. 3) The crack propagation rate in the constant stress level is faster as the grain size gets larger, the ratio of hardness lower and volume fraction smaller.

• Journal of the Korean Statistical Society
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• v.24 no.1
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• pp.45-64
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• 1995

When a random sample is taken from a certain class of discrete and continuous distributions whose support depend on two parameters, we could find that there exists the complete and sufficient statistic for parameters which belong to a certain class, and fomulate the uniformly minimum variance unbiased estimator (UMVUE) of any estimable function. Some UMVUE's of parametric functions are illustrated for the class of the distribution. Especially, we find that the UMVUE of some estimable parametric function from the truncated normal distribution could be expressed by the version of the Mill's ratio.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.1
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• pp.84-89
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• 2005

This paper presents a control algorithm for a large salient-pole synchronous motor fed by a Load Commutated Inverter (LCI). Many papers have been presented in the past few years on the justification, design, and application of variable-speed drive. The focus of this paper is on high torque operation and the estimation of initial rotor position. The results of simulation indicate that it is possible to produce the maximum torque and estimate the initial rotor position.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.54-55
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• 2001

The experiments were conducted to evaluate the feeding values of red pepper seed (Exp. 1) and to investigate its dietary supplementation on layer performances (Exp. 2). The values of TME, TMEn and average TAAA determined by force-feeding 14 roosters (Hy-line) were 2.83 kcal/g, 2.94 kcal/g and 82.72%, respectively. a total of 200 layers (ISA-brown) was divided into 4 groups with 5 replicates of 10 birds per replicate, and fed the experimental diets containing different level of red pepper seed (0, 3, 5, 10%). There were no differences in performances of laying hens among treatments. Liver lipids in all groups containing red pepper seed were significantly reduced as compared to those of control (P＜0.05).

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.49-51
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• 2001

Betaine functions as an osmoregulators in the cells and its inclusion can spare the choline, carcass fat reduction. Thus, two hundred eighty eight of seventy eight weeks old laying hens were fed with 0, 500, 1,000, 2,000 ppm betaine addition during the environmentally high temperature stress. Basal diets contained 16% CP and 2,800 ME. Egg production, feed intake, feed conversion were examined for eight weeks. Egg qualities, liver betaine, blood osmolarity, AntiDiuretic Hormone(ADH) were measured at the end experiment. Egg production of hens fed 500, 2,000 ppm dietary betaine and showed significance between control and 2,000 ppm betaine treatment(P＜0.05). ADH of blood sera tended to increase as dietary supplemental betaine increased. The results of this experiments indicated that dietary supplemental betaine was able to improve the performance, eggshell breaking strength, liver betaine in this experiment.

• Corrosion Science and Technology
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• v.11 no.6
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• pp.247-256
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• 2012

Harmonic current was measured for a dummy cell with various values of resistance, and the procedure developed through the measurements was applied to the investigation of effects of the amplitude of applied frequency and applied potential on the harmonic current of a stainless steel and a carbon steel in chloride containing solutions. From the measurements of harmonic current in the dummy cell, the optimum values of applied frequency and applied potential in harmonic current measurements were found to be 1 mHz and 20 mV (or lower), respectively. Increase in harmonic current with applied frequency was observed in the case where the level of harmonic current is low as in a stainless steel. Decrease in polarization resistance was also noted in this corrosion system with either increasing applied frequency or decreasing applied potential. However, no obvious effects of applied frequency was observed on harmonic current and polarization resistance in a carbon steel in which the level of harmonic current is high.

• Journal of the Ergonomics Society of Korea
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• v.16 no.2
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• pp.73-82
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• 1997

Daily exposure to constrained body postures and deviations from neutral postures over a long period may result in discomfort as well as pains and aches in the muscles, joints, tendons, and other soft tissues. Furthermore, it was known that poor body postures are a major cause of musculoskeletal disorders in industry. Therefore, in this study, comfort ranges of joint motions were obtained as a criterion for evaluating body postures and designing workplaces ergonomically, which were bases on subjects' perceived discomfort level estimated by magnitude estimation. Nineteen healthy male subjects participated in the laboratory study. They results showed that comfort ranges of joint motions occurred in the wrist, elbow, neck, and ankle were little less than their normal range of joint motions, but those in the back(L5/S1) and hip joint were much less than their normal ones. This fact implies that the back and jip movements are more stressful than the other joints movements. It is expected that comfort ranges of joint motions can be used as a valuable guideline when designing and evaluating workplaces.

• Journal of Plant Biology
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• v.37 no.1
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• pp.27-36
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• 1994

For establishing a transformation system of rice, an efficient introduction of foreign genes into embryogenic cell suspension by particle bombardment was conducted. The particle inflow gun based on the acceleration of DNA-coated tungsten particles using pressurized helium was constructed for delivery of DNA into rice cells. Several bombardment parameters were optimized using the transient expression of GUS gene. The conditions that gave the highest GUS gene expression of about 1000 blue spots per g fresh weight of bombarded cells include treatment of the cells with 0.5 M osmotic pressure, and use of the 410 kPa helium, 110 mm target distance, 13 mm syringe filter holder and 5 $\mu$L DNA/tungsten mixtures. It was also confirmed that rice actin promoter-intron construct gave the highest expression of all promoter-sequences studied. Eight weeks after the bombardment, stably transformed calluses were obtained on the selection medium containing 100 mg/L G418 and showed the strong activity in in situ GUS assay.